Queries

Queries $Q$ are added to the rules for expressions $e$ .

$$\begin{array}{rrcll} \textrm{Queries} & Q &::=& (q \; [\math... ...OM} [()] \mid \hat{E} \; [o] \mid \hat{E} \; [o], O \end{array}$$

$$\begin{array}{rrcll} \textrm{Projections} & P &::=& \ast & \... ...sf{RANK}() \\ &&& \mathsf{COUNT}(*) \\ &&& a(E) \end{array}$$

Additionally, an SQL expression may be inserted into normal Ur code with the syntax $(\mathsf{SQL} \; E)$ or $(\mathsf{WHERE} \; E)$ . Similar shorthands exist for other nonterminals, with the prefix $\mathsf{FROM}$ for $\mathsf{FROM}$ items and $\mathsf{SELECT1}$ for pre-queries.

Unnamed expression columns in $\mathsf{SELECT}$ clauses are assigned consecutive natural numbers, starting with 1. Any expression in a $p$ position that is enclosed in parentheses is treated as an expression column, rather than a column pulled directly out of a table, even if it is only a field projection. (This distinction affects the record type used to describe query results.)